RE: Brushless ESC to Battery Connections
I'm not familar with that plane, but if you are running two motors, each with its own ESC, then you are correct. Both ESCs get connected to the battery. If the two ESCs have BECs that power up the receiver, then you should find out if you can plug both in at the same time, or if you need to disconnect one BEC.
The BEC is a "Battery Eliminator Circuit", which is just a voltage regulator inside the ESC. This regulates your battery voltage down to about 5V to power the receiver. Some types of voltage regulators can be connected together in parallel, giving you more max current capability, while other types of voltage regulators can be damaged if more than one is connected together. When in doubt, disconnect one of them. To do this, you just clip the center lead on one of the ESC leads going to the receiver. This disconnects the BEC output from that ESC, allowing the other ESC's BEC to power the receiver by itself. Alternatively, if you are using a Y-connector to connect both ESCs to the receiver, then just clip the center wire on one side Y-harness, that way you don't modify the ESC lead, and can use that in another plane without having to reconnect the center wire.